{{ definedVar                     is     defined ? 'ok' : 'ko' }}
{{ definedVar                     is not defined ? 'ko' : 'ok' }}
{{ undefinedVar                   is     defined ? 'ko' : 'ok' }}
{{ undefinedVar                   is not defined ? 'ok' : 'ko' }}
{{ zeroVar                        is     defined ? 'ok' : 'ko' }}
{{ nullVar                        is     defined ? 'ok' : 'ko' }}
{{ nested.definedVar              is     defined ? 'ok' : 'ko' }}
{{ nested['definedVar']           is     defined ? 'ok' : 'ko' }}
{{ nested.definedVar              is not defined ? 'ko' : 'ok' }}
{{ nested.undefinedVar            is     defined ? 'ko' : 'ok' }}
{{ nested['undefinedVar']         is     defined ? 'ko' : 'ok' }}
{{ nested.undefinedVar            is not defined ? 'ok' : 'ko' }}
{{ nested.zeroVar                 is     defined ? 'ok' : 'ko' }}
{{ nested.nullVar                 is     defined ? 'ok' : 'ko' }}
{{ nested.definedArray.0          is     defined ? 'ok' : 'ko' }}
{{ nested['definedArray'][0]      is     defined ? 'ok' : 'ko' }}
{{ object.foo                     is     defined ? 'ok' : 'ko' }}
{{ object.undefinedMethod         is     defined ? 'ko' : 'ok' }}
{{ object.getFoo()                is     defined ? 'ok' : 'ko' }}
{{ object.getFoo('a')             is     defined ? 'ok' : 'ko' }}
{{ object.undefinedMethod()       is     defined ? 'ko' : 'ok' }}
{{ object.undefinedMethod('a')    is     defined ? 'ko' : 'ok' }}
{{ object.self.foo                is     defined ? 'ok' : 'ko' }}
{{ object.self.undefinedMethod    is     defined ? 'ko' : 'ok' }}
{{ object.undefinedMethod.self    is     defined ? 'ko' : 'ok' }}
